Limit definition for derivation of f(x) HELPtutoring my daughter and I'm stuck

Click For Summary
SUMMARY

The discussion focuses on using the limit definition to find the derivative of the function f(x) = x^2 - 4x. The derivative is defined as the limit of the ratio [f(x+h) - f(x)]/h as h approaches 0. The calculation involves substituting f(x+h) into the limit definition, leading to the expression 2hx + h^2 - 4h. This method is essential for understanding the foundational concepts of calculus as outlined in Larson's "Precalculus: Graphing with Limits".

PREREQUISITES
  • Understanding of limits in calculus
  • Familiarity with the concept of derivatives
  • Basic algebraic manipulation skills
  • Knowledge of polynomial functions
NEXT STEPS
  • Study the limit definition of the derivative in detail
  • Practice calculating derivatives using the limit definition with various polynomial functions
  • Explore the relationship between derivatives and tangent lines
  • Review examples from Larson's "Precalculus: Graphing with Limits" for additional context
USEFUL FOR

Students learning calculus, educators teaching derivative concepts, and anyone seeking to strengthen their understanding of limit definitions in mathematics.

epatjn
Messages
1
Reaction score
0

Homework Statement



Here's the question...use the limit definition to find the derivation of f(x) = x^2-4x

Homework Equations



does this use the definition of the derivative formula (using Larson, et al 4th edition of Precaclulus graphing with limits...and trying to teach someone what to do, but am at a loss at present on what to do...

The Attempt at a Solution

 
Physics news on Phys.org


epatjn said:

Homework Statement



Here's the question...use the limit definition to find the derivation of f(x) = x^2-4x

Homework Equations



does this use the definition of the derivative formula (using Larson, et al 4th edition of Precaclulus graphing with limits...and trying to teach someone what to do, but am at a loss at present on what to do...

The Attempt at a Solution

I don't have the Larson book, but I assume it defines the derivative (not _derivation_) of f at x to be the limit of the ratio [f(x+h) - f(x)]/h as h --> 0. Well, you can calculate f(x+h) and you know f(x), so you can see what the ratio is equal to. Then you can see what it becomes closer and closer to as h becomes smaller and smaller.

RGV
 


f(x)= x^2- 4x so f(x+h)= (x+h)^2- 4(x+h)= x^2+ 2hx+ h^2- 4x- 4h

f(x+h)- f(x)= x^2+ 2hx+ h^2- 4x- 4h- (x^2- 4x)= 2hx+ h^2- 4h
 

Similar threads

  • · Replies 20 ·
Replies
20
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
10
Views
8K
  • · Replies 3 ·
Replies
3
Views
3K
Replies
7
Views
2K
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 5 ·
Replies
5
Views
8K
Replies
4
Views
2K
Replies
65
Views
8K